Folding display frames are commonly used at trade shows for holding display panels assembled into a temporary display stand. Photomural displays and other graphics, projection screens, product display shelves, and the like are commonly mounted on the portable display stands.
Folding display frames typically comprise a number of rigid frame members pivotally connected together at their ends in a collapsible and portable form. The framework, in its expanded or open state, commonly consists of a grid of horizontal and vertical rod members forming an array of cubicles. The frame is carried to the exhibition hall in its collapsed form and is then erected to form the rigid structural framework for the display stand. Display panels, which are mounted to the display frame, and other structural members of the supporting frame also are carried to the trade show in a compact form. The entire folding display system is then assembled into the finished display unit. When the trade show is completed, the display frame is collapsed and the display system is carried away in its portable form.
In a typical three-dimensional framework, a plurality of rod members are pivotally connected together to permit collapsing of the framework into a compact form in which the rod members lie substantially parallel to each other. Except where the framework is assembled in a substantially permanent structure, the rod members are pivotally joined at their ends to some type of hub, so that the rods can be rotated relative to each other as the framework is adjusted between its open, expanded configuration and its closed, compact storage configuration. Examples of such prior art folding frameworks are found in U.S. Pat. No. 4,471,548, Goudie; U.S. Pat. No. 4,479,340, Alphonse, et al.; U.S. Pat. No. 4,512,097, Zeigler; U.S. Pat. No. 4,580,375, Nodskov, et al.; and U.S. Pat. No. 4,276,726, Derus.
One of the objectives in designing folding display frames is to make the structure light in weight and compact in its folded form to enhance ease of transportation and storage when the framework is not in use. At the same time, the framework, when fully expanded into its useful configuration, must be strong and fairly rigid. The framework not only must be strong enough to give adequate support to the display panels and the items mounted on them, but it must also withstand abuse, particularly when being constantly folded and unfolded.
Large diameter thin-walled metal tubes normally provide maximum strength-to-weight ratios. However, the hubs to which the tubes are pivotally joined must be made light and compact to reduce the space required by the hubs when they are brought together in the collapsed configuration of the framework. In the past, attempts to utilize small hubs and thin solid rods have resulted in a relatively fragile structure, whereas use of larger diameter tubular rods has resulted in bulkier and heavier hubs.
A commonly used display frame configuration is one in which the upright frame has a curved configuration, i.e., the frame is arcuate in the top plan view shape of the expanded frame. Such a configuration tends to be more stable than an expanded display frame in a flat form. Therefore, it is desirable for the portable display frame to be quickly and easily assembled into a stabilized curved configuration and then be easily collapsed from this configuration without difficulty.
Display booth spaces rented in exhibition halls are generally of standard sizes; a standard trade show booth is ten feet wide, for example. As a result, the folding display frames are commonly assembled into an expanded configuration which stays within the standard ten-foot-wide space. However, the designs of prior art portable display frames tend to limit the configurations of the display stands which are able to fit within the standard booth space.
Thus, there is a need for a simple, lightweight, strong and rigid folding display frame which can be quickly and easily unfolded and assembled into an expanded configuration used in supporting various types of display stands at trade shows. The display frame also should be easily expanded into the desired, curved, stabilized configuration normally used in trade show display stands. The frame also should be quickly and easily folded into its compact configuration when not in use. The particular configuration in which the display frame is used should not interfere with ease of folding the framework into its compact form. The configuration of the display frame also should not require a large volume or weigh too much when the frame is folded, since these folding frameworks must be conveniently transported to and from the exhibition hall.